$-8mn - mp - 9m + 4 = 2n - 3$ Solve for $m$.
Solution: Combine constant terms on the right. $-8mn - mp - 9m + {4} = 2n - {3}$ $-8mn - mp - 9m = 2n - {7}$ Notice that all the terms on the left-hand side of the equation have $m$ in them. $-8{m}n - 1{m}p - 9{m} = 2n - 7$ Factor out the $m$ ${m} \cdot \left( -8n - p - 9 \right) = 2n - 7$ Isolate the $m$ $m \cdot \left( -{8n - p - 9} \right) = 2n - 7$ $m = \dfrac{ 2n - 7 }{ -{8n - p - 9} }$ We can simplify this by multiplying the top and bottom by $-1$. $m= \dfrac{-2n + 7}{8n + p + 9}$